Company email, January 2012 in response to the standard Barnivore question:

"Our only packaged beers that contain animal ingredients are Breakfast Stout, KBS, and CBS, because they contain milk chocolates, and a few taproom-only beers (I.e., Honey Wheat). We do not use any animal products in our filtration. All of our products are produced on-site in Grand Rapids, Michigan."

Company email: February 2010
"Yes indeed all of our non chocolate beers are indeed vegan. We have been pleased with our decision and it appears that our customers are also happy. Breakfast Stout, Kentucky Breakfast Stout and Canadian Breakfast Stout are currently the only chocolate beers we make. We occasionally do a honey beer on tap here at the pub only and we once made a beer onsite called Hole Mole that also had chocolate. Other than that all of our beers are vegan."

Company email: December 2009
"Thanks for your interest, and Yes we have successfully integrated a vegan fining agent into our brewing process. This not only makes us feel a lot better about our beers, but has given us incredible clarity. I can't believe that anyone would use anything else. It
does cost us more, and we had to develop processes for its integration, but we feel great about telling people that our (non-milk) beers are all vegan. We started using this fining agent exclusively in July of 2009 so anything brewed thereafter is vegan! I
hope you get a chance to enjoy some of our beers. Thanks for
supporting Founders!"

Company email: March 2009
"We are struggling with this very subject now and are almost completely vegan. We absolutely want and plan to be vegan as soon as possible. We were told by a supplier that our fining agent was vegan so we though we were, but found out from the manufacturer that not to be true. Other than our finings and chocolate in a couple of beers, we do not use any animal products or byproducts in any of our beers. We are currently doing trials of vegan finings and will soon be completely vegan. All of our dark beers however (with the exception of Breakfast Stout and KBS which have chocolate in them) are vegan as we do not use finings in them (Porter, Imperial Stout, Oatmeal Stout). We’ll get there soon… I hope that this info is helpful."

Also from March 2009:
Company Email via Kevin M
"Although we do not filter our products we have used some of these agents in our beers. Some products we don't use any clarifying agents like our Kentucky Breakfast Stout and Backwood's Bastard."

Company Email: December 2008
"We do not use any of the mentioned processing agents in the production of
our beer. We believe that great beer comes from great ingredients. I am
happy to say that all of our beers except Breakfast Stout and Kentucky
Breakfast (KBS) are vegan friendly as well. Of course we use chocolate
in our world famous Breakfast and Kentucky Breakfast Stouts and these
chocolates do contain milk. All of our beers are unfiltered so they
retain all of their precious goodness and do not contain any of that
@% listed below. We do use a synthetic fining agent to aid in the
clarification of our beers however, but do not use isinglass or animal
derived gelatin."

Company Email: November 2008
"We do not use isinglass in any of our products. Kona and Sumatra coffee’s are used and European chocolates."